CANANDAIGUA, N.Y. — The investigation into a fatal crash involving NASCAR star Tony Stewart continues, but Ontario County sheriff Philip Povero said Monday there were currently no criminal charges pending.

"At this time, there are no facts that exist that support any criminal behavior or conduct or any probable cause of a criminal act in this investigation," he said.

"This is an open investigation. What I have just said is not indicative that the investigation is over or conclusions have been made, but that we are continuing to gather all information."

Povero said the investigation into the incident in which a sprint car driven by Stewart struck and killed 20-year-old Kevin Ward Jr. at Canandaigua Motorsports Park was ''progressing well."

He also said an autopsy conducted Monday by the Ontario County coroner found Ward's cause of death to be massive blunt trauma.

Ward Jr. was struck by Stewart's car after Ward exited his car and walked down the track under a caution period. Ward's body was thrown and he was fatally injured.

Funeral arrangements for Ward Jr. were announced earlier Monday. Visitation will be held noon-4 p.m. ET and 6-9 p.m. ET, Wednesday at Trainor Funeral Home in Boonville, N.Y., according to owner Carl Trainor. The funeral will be Thursday at 11 a.m. ET, though Trainor said a venue has not yet been chosen.

Earlier Monday, Mike Arning, director of communications for Stewart-Haas Racing, told USA TODAY Sports that Stewart's sprint car schedule was indefinitely suspended and he was still mulling whether he would return to NASCAR this weekend at Michigan International Speedway.

"The decision to compete in this weekend's NASCAR Sprint Cup Series event at Michigan will be Tony's, and he will have as much time as he needs to make that decision," Arning said in an email to USA TODAY Sports.

"It is still an emotional time for all involved, Tony included. He is grieving, and grief doesn't have a timetable."

Stewart sits in his car in the garage area at Pocono International Raceway while talking with crew chief, Greg Zipadelli. The photo, taken in 1999, is from Stewart's rookie season in the Cup series. Russ Hamilton, AP

Tony Stewart (20) flies through the air after an accident during the 2001 Daytona 500. Despite winning three Cup championships and racking up 47 career wins, Stewart has yet to win a Daytona 500. Jim Topper, AP

Stewart drives through the first turn at the Indianapolis Motor Speedway during the final practice session before the 85th running of the Indianapolis 500 in 2001. Stewart occasionally raced in the IZOD IndyCar series from 1996-2001. Michael Conroy, AP

Stewart (right) celebrates atop the flag stand near fans at Daytona International Speedway after winning the 2005 Pepsi 400. According to National Motorsports Press Association (NMPA), Stewart is one of the Top 10 most popular drivers in NASCAR. David Graham, AP

Stewart, driver of the No. 14 Office Depot/Mobil 1 Chevrolet, celebrates in after winning the NASCAR Sprint Cup Series Ford 400 and the 2011 Series Championship at Homestead-Miami Speedway on November 20, 2011 in Homestead, Florida. The title was Stewart's third Cup series championship, having previously won in 2002 and 2005. Jared C. Tilton, Getty Images

President Barack Obama (right) talks with NASCAR Sprint Cup Series champion Tony Stewart during an event to honor him and the other 2011 Sprint Cup Series drivers at the White House on Tuesday, April 17, 2012. Evan Vucci, AP

Stewart drives the No. 14 Chevrolet during the Feed the Children Prelude to the Dream at Eldora Speedway on June 6, 2012 in Rossburg, Ohio. Stewart bought Eldora Speedway in 2004. Chris Graythen, Getty Images